When a change occurs in one or more of the factors that determine type of farming in an agricultural area, making it necessary to abandon an established system or to make more or less radical changes in it, the farmers in the area strike out more or less blindly in all directions. They try new crops and new kinds of livestock farming. Many of their experiments fail, because the new enterprises are not adapted to local conditions. In some instances none of the experiments made by farmers under such conditions have resulted in success. As a result, the agriculture of considerable regions has declined, much of the land being abandoned. A few examples may be cited: Previous to about the beginning of the present century rice culture in the United States was confined to inter-tidal flats above the reach of salt water along the Atlantic coast. These lands are very soft and rice production on them is necessarily largely a matter of hand labor. When rice culture developed on a large scale on the prairies of Louisiana, Texas, and Arkansas, where the use of labor-saving machinery is feasible, the resulting increase in production brought the price of rice below cost of production on the Atlantic seaboard. It soon became apparent that rice culture must be abandoned there. Cotton, truck crops, forage crops for livestock, were all tried on the rice lands without success. The result was the complete abandonment of these lands. Another illustration is in the areas near the Gulf and Atlantic coasts where the yield of cotton was already low and where, in consequence, the usual methods of combating the boll weevil were not applicable. After the weevil invasion it became necessary to abandon cotton in much of this region.